Any change made to a document is saved under Version Control. You can see the version of a document by looking at "History" tab the bottom of the document. For example, on the following document the version is 3.1 and has last been modified by "Administrator". You can also see who last modified the document and the time the change was performed at the top of the page:
"History" as it appears using the Flamingo Skin
As the image shows, the document version consists of two numbers, separated by a dot: <Major>.<Minor>. The XWiki versioning system allows the distinction between major and minor edits. When, the user has the option to decide whether his edit brings major or minor changes to the document. Saving a major version will increase the first component and reset the second to "1", while a minor version will just increase the second component.
Clicking on the "History" button when viewing a page displays all the versions that were previously saved:
Besides listing the document versions, the history page can be used to perform other actions as well:
- compare any two versions
- set an older version as the current version (rollback); available only if the user has edit rights on the document
- delete a version completely from the history (useful for removing spam, for example); available only if the user has administration rights
- delete an entire version range from the history; also available only if the user has administration rights
By default, minor edits do not appear in the document history. The option "Show minor edits" will list all the versions, including minor ones.
The comparison between two document versions highlights the differences between document properties (title, content, parent, syntax, etc.), attachments, objects and class properties.
In order to compare 2 versions you need to select one of the radio buttons corresponding to the version from which you want to start the comparison. These are the buttons located in the "From" column. You will then need to select the button corresponding to the version you want to compare the previously selected version against. These buttons are located in the "To" column. You may choose to include minor edits in the comparison. After selecting the 2 versions you wish to compare you will need to click on "Compare selected versions". Depending on the changes you have made you will get a result similar to this:
"Changes for document" as they appear using the Flamingo Skin
Note that the comparison starts with a Summary (7.0RC1+) that groups the changes in 4 categories: Page Properties, Attachments, Objects and Class Properties. A category is displayed only if there are related changes. Except for 'Page properties', the rest of the categories can be expanded to see which items have been added, deleted or modified. Each item provides a link to the details that are listed below the Summary.
The comparison details lists all the items (page properties, attachments, objects, class properties) that have been added, deleted or modified. For each item you can see what properties have been modified and the exact modifications. For text attachments you can even see the changes made to the attachment content between two versions of the attachment (7.0RC1+). The changes made to the object properties of type Password and Email are obfuscated for privacy reasons.